Showing papers by "Jeffrey A. Reimer published in 1981"

Effects of inert gas dilution of silane on plasma‐deposited a‐Si:H films

Abstract: Electrical, optical, and structural characterization of hydrogenated amorphous silicon films plasma‐deposited from mixtures of SiH4 with different inert‐gas diluents reveals substantial differences in a number of properties. A general trend of increasing defect density with atomic weight of the inert gas is observed. Of specific interest to device applications is the observation that high deposition rates can be achieved concurrently with low defect densities when helium is used as a deluent.

Proton-magnetic-resonance studies of microstructure in plasma-deposited amorphous-silicon—hydrogen films

Abstract: Proton-magnetic-resonance data are presented for twenty different plasma-deposited amorphous-silicon---hydrogen films. The two-phase compositional inhomogeneity observed in these films is found to be independent of film thickness down to less than 1 \ensuremath{\mu}m. Models for various structural configurations show that these films contain heavily monohydride-clustered regions such as vacancies and voids, as well as ${(\mathrm{Si}{\mathrm{H}}_{2})}_{n}$ and Si${\mathrm{H}}_{3}$ local bonding configurations. The films also contain regions in which monohydride groups are distributed at random. Based on changes in a film whose proton NMR line shapes are metastable as deposited, a model based on strain relief is proposed for film development which explains the ubiquitous presence of the two-phase inhomogeneity. Examination of the changes in proton NMR data as a function of deposition conditions furnishes new insight on the role Si${\mathrm{H}}_{2}$ and $\mathrm{Si}{{\mathrm{H}}_{x}}^{+}$ groups have in models for the gas-phase reactions involved in the developing films. Finally, $p$- or $n$-type doping is found to increase the hydrogen content of the films, and, under heavy $p$-type doping with diborane, boron clustering may occur within the films.

Proton magnetic resonance spectra of plasma‐deposited inorganic thin films

Abstract: Proton magnetic resonance data are presented for the hydrogen alloys of plasma-deposited amorphous boron, carbon, silicon carbide, and silicon nitride. Linewidth and lineshape analysis leads to the conclusion that hydrogen nuclei are clustered in a-Si/C:H, a-C:H, and a-Si/C:H. Both a-Si/C:H and a-C:H data show that the hydrogen exists in two phases. Modeling of line- widths in a-Si/C:H indicates that the two phases are heavily hydrogenated carbon clusters imbedded in a weakly hydrogenated a-Si lattice. Finally, evidence is presented for the presence of motionally narrowed hydrogen spectra in a-Si/N:H, a-B:H, and a-C:H. It is suggested that the hydrogen nuclei giving rise to these spectra are associated with disorder modes.

Silicon‐29 cross‐polarization magic‐angle sample spinning spectra in amorphous silicon–hydrogen films

Abstract: Magic‐angle sample spinning cross‐polarization 29Si NMR spectra are reported for plasma‐deposited amorphous silicon‐hydrogen films. The data show (i) confirmation of the identification of polyhydride (SiH2)n species as seen by infrared spectroscopy and (ii) a large degree of chemical shift dispersion due to disorder in the silicon lattice.